Hydrazine

Hydrazine

Hydrazine hydrate
Names
Systematic IUPAC name Hydrazine
Other names Diamine; Diazane; Tetrahydridodinitrogen (N—N)
Identifiers
CAS Number	302-01-2 Y
3D model (Jmol)	Interactive image
3DMet	B00770
Beilstein Reference	878137
ChEBI	CHEBI:15571 Y
ChEMBL	ChEMBL1237174 N
ChemSpider	8960 Y
ECHA InfoCard	100.005.560
EC Number	206-114-9
Gmelin Reference	190
KEGG	C05361 Y
MeSH	Hydrazine
PubChem	9321
RTECS number	MU7175000
UNII	27RFH0GB4R Y
UN number	2029
InChI InChI=1S/H4N2/c1-2/h1-2H2 Y Key: OAKJQQAXSVQMHS-UHFFFAOYSA-N Y InChI=1/H4N2/c1-2/h1-2H2 Key: OAKJQQAXSVQMHS-UHFFFAOYAZ
SMILES NN
Properties
Chemical formula	N 2H 4
Molar mass	32.0452 g mol−1
Appearance	Colorless, fuming, oily liquid
Odor	ammonia-like
Density	1.021 g cm−3
Melting point	2 °C; 35 °F; 275 K
Boiling point	114 °C; 237 °F; 387 K
Solubility in water	miscible
log P	0.67
Vapor pressure	1 kP (at 30.7 °C)
Acidity (pKa)	8.10 (N2H5+)
Basicity (pKb)	5.90
Refractive index (nD)	1.46044 (at 22 °C)
Viscosity	0.876 cP
Structure
Molecular shape	Triangular pyramidal at N
Dipole moment	1.85 D
Thermochemistry
Std molar entropy (So298)	121.52 J K−1 mol−1
Std enthalpy of formation (ΔfHo298)	50.63 kJ mol−1
Hazards
Safety data sheet	ICSC 0281
GHS pictograms
GHS signal word	DANGER
GHS hazard statements	H226, H301, H311, H314, H317, H331, H350, H410
GHS precautionary statements	P201, P261, P273, P280, P301+310, P305+351+338
EU classification (DSD)	T+ N
R-phrases	R45, R10, R23/24/25, R34, R43, R50/53
S-phrases	S53, S45, S60, S61
NFPA 704	4 4 3
Flash point	52 °C (126 °F; 325 K)
Autoignition temperature	24 to 270 °C (75 to 518 °F; 297 to 543 K)
Explosive limits	1.8–99.99%
Lethal dose or concentration (LD, LC):
LD50 (median dose)	59–60 mg/kg (oral in rats, mice)
LC50 (median concentration)	260 ppm (rat, 4 hr) 630 ppm (rat, 1 hr) 570 ppm (rat, 4 hr) 252 ppm (mouse, 4 hr)
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 1 ppm (1.3 mg/m3) [skin]
REL (Recommended)	Ca C 0.03 ppm (0.04 mg/m3) [2-hour]
IDLH (Immediate danger)	Ca [50 ppm]
Related compounds
Other anions	tetrafluorohydrazine hydrogen peroxide diphosphane diphosphorus tetraiodide
Other cations	organic hydrazines
Related Binary azanes	Ammonia triazane
Related compounds	diazene triazene tetrazene diphosphene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Hydrazine is an inorganic compound with the chemical formula N
2H
4 (also written H
2NNH
2). A simple pnictogen hydride, it is a colorless flammable liquid with an ammonia-like odor. Hydrazine is highly toxic and dangerously unstable unless handled in solution. As of 2000^[update], approximately 120,000 tons of hydrazine hydrate (corresponding to a 64% solution of hydrazine in water by weight) were manufactured worldwide per year. Hydrazine is mainly used as a foaming agent in preparing polymer foams, but significant applications also include its uses as a precursor to polymerization catalysts and pharmaceuticals. Additionally, hydrazine is used in various rocket fuels and to prepare the gas precursors used in air bags. Hydrazine is used within both nuclear and conventional electrical power plant steam cycles as an oxygen scavenger to control concentrations of dissolved oxygen in an effort to reduce corrosion. Anhydrous hydrazine is corrosive towards glass, in a manner similar to hydrofluoric acid.

Each H₂N-N subunit is pyramidal in shape. The N-N single bond distance is 1.45 Å (145 pm), and the molecule adopts a gauche conformation. The rotational barrier is twice that of ethane. These structural properties resemble those of gaseous hydrogen peroxide, which adopts a "skewed" anticlinal conformation, and also experiences a strong rotational barrier.